I don't like it that much. I think that the image itself doesn't translate well into black-&-white. I hate the little angled slash on the T. And most critically, I don't think that the logo is iconic enough. It is not an image that I would immediately associate with the language. C++ doesn't have this problem since the language name itself is iconic. Java is a bit more iconic, but not as much, and not surprising, it has a logo. A logo which isn't great, but it has been around for long enough where it doesn't matter.
I kept the dart image oriented upwards. It further communicates uprightness, rigidity, and even being a little bit boring. I could have tilted the logo to the left slightly, which would have added some energy and movement to the logo, but that reduced the impression rigid professionalism.
I used a font with serifs since they present an impression of stability, strength, tradition, and integrity as opposed to the modern air presented by fonts with a san-serif. Truly, the font choice seems a little 1990's computer world. This might seem counter-intuitive for a futuristic technology company, but that very reality I think presents the opportunity to use a brand personality counter to the parent company, relying on the strength of both brands to walk hand-in-hand.
Google is modern, futuristic, playful, and tech-savvy, but as Dart shows, they know when integrity, foundation, and respectability matter. Sometimes, being boring is precisely what's needed.